A008341 a(n)=1, a(n+1) = lcm(a(n),b(n)) / gcd(a(n),b(n)), where {b(n)} = {fibonacci(n)}.

1, 1, 1, 2, 6, 30, 60, 780, 1820, 15470, 34034, 3029026, 109044936, 25407470088, 56678202504, 8643425881860, 19344810307020, 30893662060310940, 17264105268997290, 72181224129677669490

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Programs

Maple

with(combinat): A008341 := proc(n) option remember; if n = 1 then 1 else lcm(A008341(n-1),fibonacci(n-1))/gcd(A008341(n-1),fibonacci(n-1)); fi; end;

Mathematica

FoldList[ LCM[ #1, #2 ]/GCD[ #1, #2 ]&, 1, Nest[ Join[ #1, {Plus@@Take[ #1, -2 ]} ]&, {1, 1}, 20 ] ]

Extensions

Mathematica Program Aug 15 1997 (Olivier Gérard).